There are many drawbacks to currently available natural and naturally-derived antimicrobial formulations. They are expensive, and high concentrations of them (for instance, >2%) are often required to prevent microbial growth and preserve a product. Many have undesirable colors and odors, have poor stability (for example, in aqueous systems), and are not effective against a broad spectrum of microorganisms. Additionally, some such natural or naturally-derived antimicrobial mixtures cause thinning of formulations. Many are oils or extracts which limits their usage in various formulations.
There is a continuing need for low cost and safe natural preservative systems which are effective against a broad spectrum of microorganisms.